CN112143200A

CN112143200A - Polycarbonate plastic and processing technology thereof

Info

Publication number: CN112143200A
Application number: CN202011019817.5A
Authority: CN
Inventors: 蓝小华; 颜栋; 王志强
Original assignee: Shanghai Yacheng Plastic Products Co ltd
Current assignee: Shanghai Yacheng Plastic Products Co ltd
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2020-12-29
Anticipated expiration: 2040-09-25
Also published as: CN112143200B

Abstract

The application relates to the technical field of plastic products, in particular to polycarbonate plastic and a processing technology thereof. The polycarbonate plastic is obtained by injection molding of the following components in parts by mass: polycarbonate (C): 50-80 parts; ABS resin: 7-15 parts; carbon-based fibers: 5-10 parts; polylactic acid modifier: 3-6 parts; a compatilizer: 2-3.5 parts; a reinforcing auxiliary agent: 0-4 parts; 0-6 parts of other auxiliary agents. The processing technology of the polycarbonate plastic comprises the steps of drying prepared materials, mixing the polycarbonate, the polylactic acid modifier and the compatilizer into a first mixed system, mixing ABS resin and other additives into the first mixed system to form a second mixed system, mixing carbon-based fibers and a reinforcing additive into the second mixed system to form a third mixed system, injection molding and the like.

Description

Polycarbonate plastic and processing technology thereof

Technical Field

The application relates to the technical field of plastic products, in particular to polycarbonate plastic and a processing technology of the polycarbonate plastic.

Background

Polycarbonate is a commonly used plastic material, and has been widely used in daily life due to its excellent chemical resistance, high transparency, good moisture absorption rate and good mechanical properties. Since polycarbonate articles can be sterilized by steam, detergent and radiation, they are often used for tableware, and in order to further improve the physical and chemical properties of polycarbonate, polycarbonate and polyethylene terephthalate are often made into plastic alloys in the prior art to improve the mechanical strength of polycarbonate, such as toughness, impact resistance, etc. The Chinese patent with publication number CN105368032A discloses a preparation method of toughened and modified polycarbonate, which comprises the following steps: step 1, preparing modified PET; step 2, preparing modified rigid nano filler; and 3, taking 110-150 parts by weight of polycarbonate, 6-15 parts by weight of modified PET, modified rigid nano filler, 6-15 parts by weight of chlorinated polyethylene, 5-12 parts by weight of styrene/methyl methacrylate copolymer and 6-15 parts by weight of polybutyl acrylate, putting into a double-screw extruder, and carrying out melt blending and molding.

In the prior art, because the PET plastic is used, the PET plastic has poor heat resistance and is easy to generate harmful substances at high temperature, so that the PET plastic is not suitable for some application scenes such as tableware, mineral water buckets, tooth cups and the like which need to be directly taken into the body or contact with the oral cavity and the skin of a human body.

As an alternative to PET plastics, polycarbonate is modified sometimes with glass fibers to enhance toughness, tensile strength and stiffness of the polycarbonate. For example, the Chinese patent with the publication number of CN101328310B discloses a toughened and reinforced PC/ABS composite material and a preparation method thereof, wherein the composite material comprises the following components in percentage by weight: 20-80% of PC resin, 10-40% of ABS resin, 5-40% of glass fiber, 2-10% of toughening agent, 1-20% of compatilizer and 0.5-4% of other auxiliary agents. The method comprises the following specific steps: weighing various materials except the glass fiber, mixing the materials in a high-speed mixer for 3-5 minutes, adding the uniformly mixed materials into a double-screw extruder, wherein the glass fiber is added from a first exhaust port, the temperature from a feeding port to an extrusion die head is respectively 200-230 ℃, 220-250 ℃, 240-260 ℃, 250-270 ℃, 260-280 ℃, and the rotating speed of a main machine is 20-50 Hz, and then preparing a sample by using a plastic injection molding machine.

However, during the use of the glass fiber, after the flying glass fiber is sucked by workers, the lungs of the workers can be damaged. In addition, glass fiber is not an ideal processing material because it causes a series of occupational diseases such as skin allergy and corneal inflammation.

Disclosure of Invention

Aiming at the defects in the prior art, the first application of the application aims to provide a polycarbonate plastic, and on the premise of ensuring the mechanical strength and the heat resistance, the use of PET and glass fiber is eliminated from raw materials. Has better safety for both producers and users.

The second application of the present application aims to provide a processing technology of the above polycarbonate plastic, and the processed polycarbonate plastic has good safety, weather resistance and mechanical strength, and is not easy to deform due to external impact.

The above object of the present application is achieved by the following technical solutions: the polycarbonate plastic is obtained by injection molding of the following components in parts by mass:

polycarbonate (C): 50-80 parts;

ABS resin: 7-15 parts;

carbon-based fibers: 5-10 parts;

polylactic acid modifier: 3-6 parts;

a compatilizer: 2-3.5 parts;

a reinforcing auxiliary agent: 0-4 parts;

0-6 parts of other auxiliary agents.

In the technical scheme, a polycarbonate and ABS resin mixed system is adopted, so that the plastic alloy with good fluidity and high toughness can be obtained, meanwhile, carbon-based fibers and polylactic acid modifiers are added into the polycarbonate and ABS resin mixed system, and the overall strength of the obtained polycarbonate plastic is improved through the reinforcing effect of the carbon-based fibers and the bonding effect of the polylactic acid modifiers.

The compatilizer is added to improve the solubility of the polylactic acid modifier in a mixed system of polycarbonate and ABS resin, so that the overall structure of the polycarbonate plastic is more uniform, and the strength of the polycarbonate plastic is further improved.

In the process, the carbon-based fiber is used for replacing the glass fiber, so that the processing process is safer, and the lung and the skin of a producer are not easily damaged. Meanwhile, the polycarbonate plastic material excludes the use of PET, has better heat resistance, and is not easy to influence the health condition of users in the process of manufacturing daily necessities and using the daily necessities.

The present application may be further configured in a preferred example to: the carbon-based fiber is a carbon nano tube, and the carbon nano tube is activated by mixed acid.

The carbon nano tube has stronger rigidity, and the surface of the activated carbon nano tube has more defect structures, so that more active reaction sites can be formed on the surface of the carbon nano tube, the mixed crosslinking structure of the carbon nano tube, polycarbonate, ABS resin and polylactic acid is facilitated, and the mechanical strength and the toughness of the polycarbonate material are further improved.

The present application may be further configured in a preferred example to: and the carbon nano tube is activated and then subjected to surface nickel plating treatment.

After the nickel plating treatment is carried out on the carbon nano tube, on one hand, the nickel can play a certain sterilization and disinfection effect, and simultaneously, the hardness and the strength of the carbon nano tube can be improved, so that the integral mechanical strength of the polycarbonate plastic is improved. In addition, the nickel-loaded carbon nanotube has better electrical properties, and the surface generally has better reactivity, so that the carbon nanotube has better compatibility with other materials.

The present application may be further configured in a preferred example to: the polylactic acid modifier is a chitosan grafted polylactic acid compound.

The polylactic acid and the chitosan are connected, the chitosan has better crosslinking performance, and the surface of the chitosan has more crosslinking sites, so that on one hand, the polylactic acid and other components are facilitated to form a more compact grid structure, the integral strength is improved, on the other hand, the chitosan is also facilitated to inhibit the degradation of the polylactic acid, and the weather resistance of the polycarbonate plastic is further improved.

The present application may be further configured in a preferred example to: the reinforcing additive comprises 1.2-2 parts by mass of epoxy resin, and the epoxy value of the epoxy resin is greater than 0.35.

The epoxy resin is thermosetting resin, and can generate cross-linking winding effect with substances such as carbon-based fibers in a system in the processes of heating, melting and injection molding, so that the strength and the impact resistance of the material are further improved. In addition, the epoxy resin is also beneficial to enabling the material to be easier to mold in the processing process, playing a role in improving the fluidity and improving the processing performance of the material.

The present application may be further configured in a preferred example to: the reinforcing auxiliary agent further comprises 0.2-1.5 parts by mass of a thermoplastic polyurethane elastomer.

The thermoplastic polyurethane elastomer is a thermoplastic elastomer, has good flowability in the processing process, and contributes to improving the wear resistance and toughness of the polycarbonate main material. In addition, the thermoplastic polyurethane elastomer is of a thermoplastic structure, can act together with thermosetting epoxy resin in the processing process, and forms a cross-linked network structure through hydrogen bond interaction, so that the overall strength is further improved.

The present application may be further configured in a preferred example to: the reinforcing auxiliary agent further comprises 1.5-2.5 parts by mass of gelatin.

The gelatin has the performance similar to that of a surfactant, can improve the mutual crosslinking effect between the reinforcing aids, has good compatibility with the carbon-based fiber, and is helpful for guiding other reinforcing aids to be further crosslinked with active sites on the surface of the carbon nano tube, so that the mechanical strength of the obtained polycarbonate plastic is further improved.

The present application may be further configured in a preferred example to: the other auxiliary agents comprise 0.1-0.5 part by mass of antioxidant, 0-4 parts by mass of color master batch, 0.1-0.3 part by mass of lubricant and 0.3-0.6 part by mass of hydrolysis resistance agent.

In the technical scheme, the antioxidant can improve the weather resistance of the polycarbonate, and the color master batch is used for color mixing of the polycarbonate plastic. The addition of the lubricant can improve the demolding performance of the processing of the polycarbonate plastic, and the hydrolysis resistance agent is used for improving the weather resistance of the polylactic acid, so that the material is not easy to damage in the long-term use process, thereby further improving the quality and the weather resistance of the polycarbonate plastic.

The present application may be further configured in a preferred example to: the compatilizer is maleic anhydride grafted polypropylene, the maleic anhydride grafted polypropylene has a good compatibility modification effect, and compared with other compatilizers, the compatilizer has a good compatibility effect in a polycarbonate-ABS resin-polylactic acid system, and is beneficial to improving the integral uniformity of plastics.

The second application aim of the application is realized by the following technical scheme: a processing technology for processing the polycarbonate plastic comprises the following steps:

s1, weighing polycarbonate, ABS resin, carbon-based fiber, polylactic acid modifier, compatilizer, reinforcing additive and other additives, and fully drying for later use;

s2, mixing polycarbonate, polylactic acid modifier and compatilizer, heating to 270-280 ℃, preserving heat and fully mixing for 60-150S to obtain a first mixed system

S3, adding ABS resin and other auxiliaries into the first mixed system, cooling to 255-260 ℃, preserving heat, and fully mixing for 60-90 seconds to obtain a second mixed system;

s4, adding carbon-based fibers and a reinforcing auxiliary agent into the second mixed system, heating to 285-290 ℃, heating for 30-40S, and cooling to 235-245 ℃ to obtain a third mixed system;

s5, performing injection molding on the third mixed system, wherein the injection pressure is 70-150 MPa, the mold temperature during injection is 140-170 ℃, the screw rotation speed is 30-50 rpm, after injection is completed, the mold temperature is cooled to 70-80 ℃ at the speed of 5-8 ℃/min, and then demolding is performed.

In the technical scheme, the polycarbonate and the polylactic acid modifier are mixed through the compatilizer, and the polylactic acid modifier is solubilized through the compatilizer, so that the effect of improving the uniformity is realized. Then, the temperature is reduced, the ABS resin and other additives are added, and under the condition that the polylactic acid is fully dispersed in the polycarbonate, the ABS resin can be more uniformly distributed in the initial cross-linked state of the polylactic acid and the polycarbonate in the adding process, and the polylactic acid is not easy to agglomerate in a system.

After the systems are mixed, the carbon-based fibers are added, the polycarbonate and polylactic acid modifiers can be crosslinked, wound and positioned around the carbon-based fibers through heating and stirring, and a crosslinking system formed by the carbon-based fibers and other polymers can be cured after cooling, so that a multi-branched crosslinking mixed system taking the carbon-based fibers as an anchor rod is further formed, and the strength is better.

And the third mixed system is subjected to injection molding in an injection molding mode, is subjected to cooling and demolding, and is kept at a uniform temperature drop in the demolding process, so that on one hand, the cracking or defect generation of the injected sample due to too fast cooling is prevented, and on the other hand, the slow curing of the product is facilitated, and a crosslinking structure with higher strength is formed.

In summary, the present application includes at least one of the following beneficial technical effects:

1. in the application, by arranging a mixed system of polycarbonate-ABS resin-polylactic acid modifier and taking carbon-based fiber as a net-shaped structure of an anchor point member, the glass fiber is eliminated on the basis of ensuring the strength and toughness of plastic, so that the safety of the production process is improved, and the damage to a processor is reduced.

2. In the present application, the use of PET is also excluded, and therefore, harmful substances are not easily generated at high temperatures, and the heat resistance is high.

3. In the application, the epoxy resin, the thermoplastic polyurethane elastomer and the gelatin are added as the reinforcing auxiliary agents, so that the strength, the toughness and the wear resistance of the molded polycarbonate plastic are further improved.

Detailed Description

The present application is described in further detail below.

Example 1, a polycarbonate plastic, prepared by the following process:

s1, weighing polycarbonate, ABS resin, carbon-based fiber, polylactic acid modifier, compatilizer, reinforcing additive and other additives, and fully drying in an oven for later use;

s2, mixing polycarbonate, a polylactic acid modifier and a compatilizer, heating to 270 ℃, and stirring for 100S to obtain a first mixed system;

s3, adding ABS resin into the first mixed system, cooling to 255 ℃, and stirring for 75S to obtain a second mixed system;

s4, adding carbon-based fibers into the second mixed system, heating to 285 ℃, stirring for 35S, and cooling to 235 ℃ to obtain a third mixed system;

s5, injection molding the third mixed system, wherein the injection pressure is 100MPa, the mold temperature is 150 ℃ during injection, the screw rotation speed is 40rpm, after injection is completed, the mold temperature is cooled to 70 ℃ at the speed of 6 ℃/min, and then demolding is carried out.

Wherein, the proportion of acrylonitrile monomer in the ABS resin is 35%, the proportion of butadiene monomer is 13%, and the proportion of styrene monomer is 52%. The carbon-based fiber is a single-wall carbon nano tube, the polylactic acid modifier is polylactic acid, the compatilizer is maleic anhydride grafted polypropylene, and the grafting rate of the maleic anhydride grafted polypropylene is 1.2% determined by an acid-base titration method.

In example 1, the amounts of the components added are shown in Table 1.

Examples 2 to 4, a polycarbonate plastic, differ from example 1 in the amount of the individual components used. The ratios of the components in examples 2 to 4 are shown in Table 1.

Table 1: the amounts of the respective components used in examples 1 to 4

Composition (I)	Example 1	Example 2	Example 3	Example 4
					Polycarbonate resin	70.18％	76.19％	65.36％	71.79％
ABS resin	11.70％	17.54％	8.19％	15.20％
					Carbon-based fiber	9.36％	5.85％	11.70％	8.19％
Polylactic acid modifier	5.85％	3.51％	7.02％	5.26％
					Compatilizer	2.92％	2.34％	4.09％	3.51％

Example 5, a polycarbonate plastic, differs from example 1 in that the carbon-based fibers are carbon fibers having an average length of 220 μm.

Example 6, a polycarbonate plastic, differs from example 1 in that the carbon-based fibers are carbon fibers having an average length of 600 μm.

Example 7, a polycarbonate plastic, differs from example 1 in that the carbon-based fiber is a single-walled carbon nanotube, and the surface of the carbon nanotube is activated by mixed acid, and the specific activation procedure is as follows: soaking the carbon nano tube in mixed acid formed by mixing 68% nitric acid and 98% sulfuric acid in a volume ratio of 1:1 at a concentration of 200mg/mL, heating and refluxing for 3 hours, cooling and centrifuging after the reaction is finished, washing with water until the pH value is more than 6, and drying under vacuum.

Example 8, a polycarbonate plastic, differs from example 7 in that the carbon-based fibers are multi-walled carbon nanotubes.

Example 9, a polycarbonate plastic, differs from example 7 in that the polylactic acid modifier selected is a chitosan-grafted polylactic acid compound, and the preparation method thereof is as follows:

p1, putting chitosan with deacetylation degree of 60% and average molecular weight of 24000 and phthalic anhydride with mass 5 times of that of the chitosan into N, N-dimethylformamide with mass 25 times of that of the chitosan, heating to 120 ℃ under the protection of nitrogen, stirring for 6h, protecting amino, dropping the reacted solution into an ice-water mixture, filtering, collecting a filter cake, and performing vacuum drying to obtain the amino-protected chitosan.

P2, dissolving the amino-protected polysaccharide and the polylactic acid in toluene with the mass ratio of 1:3 being 8 times of that of the amino-protected polysaccharide, heating to 120 ℃ under the protection of nitrogen, fully stirring and reacting for 24h, then cooling to room temperature, pouring the product into acetone, centrifugally separating for 2min at the rotating speed of 300r/min to obtain a precipitate, fully drying, extracting with acetone in a soxhlet extractor for 24h, and then drying again to obtain the polylactic acid-amino-protected polysaccharide polymer.

P3, dissolving the polylactic acid-amino protective polysaccharide polymer obtained in the step P2 and hydrazine hydrate in water with the mass ratio of 1:20 being 2 times of that of the hydrazine hydrate, heating to 100 ℃ under the protection of nitrogen, stirring and fully reacting for 15 hours, then cooling to room temperature, washing with ethanol, washing with water, washing with a mixed solvent formed by anhydrous ethanol and anhydrous ether with the volume ratio of 1:1, and drying to obtain the chitosan grafted polylactic acid compound.

Example 10, a polycarbonate plastic, differs from example 7 in that chitosan has a degree of deacetylation of 70% and an average molecular weight of 12000.

Example 11, a polycarbonate plastic, differs from example 7 in that after the surface of the carbon nanotubes are activated, they are treated with nickel plating, and the process of nickel plating is as follows:

placing the carbon nano tube into a vapor deposition chamber, introducing nitrogen at the flow rate of 100ml/min for purging, wherein the purging time is 5min, heating the vapor deposition chamber to 150 ℃, keeping the constant temperature for 10min, and stopping introducing the nitrogen; then loading the gasified nickel tetracarbonyl into a vapor deposition chamber by taking argon as carrier gas, adsorbing the nickel tetracarbonyl on the surface of the carbon nano tube and thermally decomposing the nickel tetracarbonyl into metallic nickel, keeping the temperature for 15min, then stopping heating, and introducing the argon and the nickel tetracarbonyl; then, the temperature in the vapor deposition chamber was again lowered to 30 ℃ by purging with nitrogen.

Example 12, a polycarbonate plastic, differs from example 11 in that the polylactic acid modifier selected was a chitosan-grafted polylactic acid compound, and the preparation method of the chitosan-grafted polylactic acid compound was the same as that of example 9.

Examples 13 to 21 are different from example 7 in that a reinforcing aid is further added in step S4, and specific components of the reinforcing aid are shown in Table 2.

Table 2: ingredient lists of examples 13 to 21

In the above embodiment, the epoxy resin is bisphenol A epoxy resin, and the epoxy resin is E51 (epoxy value is 0.48-0.54). The thermoplastic polyurethane elastomer is polyester-TDI-MOCA cast polyurethane.

Example 22A polycarbonate plastic which is different from example 13 in that the epoxy resin has a type JF45 (epoxy value of 0.42 to 0.48)

Example 23, a polycarbonate plastic, differs from example 13 in that the epoxy resin is type E44 (epoxy value is 0.41 to 0.47).

Example 24, a polycarbonate plastic, differs from example 13 in that the epoxy resin is type E20 (epoxy value is 0.18 to 0.22).

Example 25, a polycarbonate plastic, differs from example 13 in that the epoxy resin is type F51 (epoxy value is 0.51 to 0.54).

Example 26, a polycarbonate plastic, differs from example 16 in that the thermoplastic polyurethane elastomer is polyether-TDI-MOCA cast polyurethane.

Example 27, a polycarbonate plastic, was different from example 19 in that the surface of carbon nanotubes was activated and then subjected to nickel plating, which was performed in the same manner as in example 11.

Example 28, a polycarbonate plastic, differs from example 27 in that the polylactic acid-based modifier selected was a chitosan-grafted polylactic acid compound, and the preparation method of the chitosan-grafted polylactic acid compound was the same as that of example 9.

Examples 29 to 33, which are polycarbonate plastics, differ from example 7 in that in step S3, other additives were added and the mass fractions of the components are shown in Table 3.

TABLE 3 ingredient lists for examples 29 to 33

Composition (I)	Example 29	Example 30	Example 31	Example 32	Example 33
						Polycarbonate resin	69.77％	66.15％	67.87％	67.87％	68.10％
ABS resin	11.63％	11.03％	11.31％	11.31％	11.35％
						Carbon fiber	9.30％	8.82％	9.05％	9.05％	9.08％
Polylactic acid modifier	5.81％	5.51％	5.66％	5.66％	5.68％
						Compatilizer	2.91％	2.76％	2.83％	2.83％	2.84％
Color master batch	0.00％	4.41％	2.26％	2.26％	2.27％
						Antioxidant agent	0.12％	0.33％	0.00％	0.34％	0.34％
Lubricant agent	0.12％	0.33％	0.34％	0.00％	0.34％
						Hydrolysis resistant agent	0.35％	0.66％	0.68％	0.68％	0.00％

Wherein, the color master batch is PC color master batch, the antioxidant is BHT, the lubricant is polyethylene wax, and the hydrolysis-resistant agent is carbodiimide.

Example 34, a polycarbonate plastic, was different from example 30 in that the surface of carbon nanotubes was activated, and then subjected to nickel plating, which was the same process as example 11.

Example 35, a polycarbonate plastic, differs from example 34 in that the polylactic acid-based modifier selected was a chitosan-grafted polylactic acid compound, which was prepared in the same manner as in example 9.

Example 36, one 35, differs in that in step S4, a reinforcing assistant is also added, and the proportions of the components in the polycarbonate plastic after the reinforcing assistant are added are as follows: polycarbonate (C): 62.96 percent; ABS resin: 10.49 percent; carbon fiber: 8.39 percent; polylactic acid modifier: 5.25 percent; a compatilizer: 2.62 percent; color master batch: 4.20 percent; antioxidant: 0.31 percent; lubricant: 0.31 percent; hydrolysis resistance agent: 0.63%; epoxy resin: 1.68 percent; polyurethane elastomer: 1.08 percent; gelatin: 2.10 percent.

Example 37, a polycarbonate plastic, differs from example 36 in that the process parameters in the steps are adjusted as follows:

s2, mixing polycarbonate, a polylactic acid modifier and a compatilizer, heating to 280 ℃, and stirring for 60S to obtain a first mixed system;

s3, adding ABS resin and other auxiliaries into the first mixed system, cooling to 260 ℃, and stirring for 90S to obtain a second mixed system;

s4, adding carbon-based fibers and a reinforcing auxiliary agent into the second mixed system, heating to 290 ℃, stirring for 30S, and cooling to 245 ℃ to obtain a third mixed system;

and S5, performing injection molding on the third mixed system, wherein the injection pressure is 70MPa, the mold temperature is 170 ℃ during injection, the screw rotation speed is 50rpm, after the injection is finished, the mold temperature is reduced to 80 ℃ at the speed of 5 ℃/min, and then demolding is performed.

Example 38, a polycarbonate plastic, differs from example 36 in that the process parameters in the steps are adjusted as follows:

s2, mixing polycarbonate, a polylactic acid modifier and a compatilizer, heating to 280 ℃, and stirring for 150S to obtain a first mixed system;

s3, adding ABS resin and other auxiliaries into the first mixed system, cooling to 260 ℃, and stirring for 60S to obtain a second mixed system;

s4, adding carbon-based fibers and a reinforcing auxiliary agent into the second mixed system, heating to 290 ℃, stirring for 40S, and cooling to 245 ℃ to obtain a third mixed system;

s5, injection molding the third mixed system, wherein the injection pressure is 150MPa, the mold temperature is 140 ℃ during injection, the screw rotation speed is 30rpm, after injection is completed, the mold temperature is cooled to 70 ℃ at the speed of 8 ℃/min, and then demolding is carried out.

Example 39, a polycarbonate plastic, differs from example 36 in that the process steps are modified as follows:

s5, performing injection molding on the third mixed system, wherein the injection pressure is 150MPa, the mold temperature is 80 ℃ during injection, the screw rotation speed is 30rpm, and then demolding.

Example 40, a polycarbonate plastic, differs from example 36 in that the process steps are modified as follows:

s3, adding ABS resin, carbon-based fibers, a reinforcing auxiliary agent and other auxiliary agents into the first mixed system, cooling to 260 ℃, and stirring for 60S to obtain a second mixed system;

s4, injection molding the second mixed system, wherein the injection pressure is 150MPa, the mold temperature is 140 ℃ during injection, the screw rotation speed is 30rpm, after injection is completed, the mold temperature is cooled to 70 ℃ at the speed of 8 ℃/min, and then demolding is carried out.

Example 41, a polycarbonate plastic, differs from example 36 in that the process parameters in the steps are adjusted as follows:

s3, adding ABS resin, carbon-based fibers, a reinforcing auxiliary agent and other auxiliary agents into the first mixed system, heating to 290 ℃, and stirring for 60S to obtain a second mixed system;

s4, injection molding the third mixed system, wherein the injection pressure is 150MPa, the mold temperature is 140 ℃ during injection, the screw rotation speed is 30rpm, after injection is completed, the mold temperature is cooled to 70 ℃ at the speed of 8 ℃/min, and then demolding is carried out.

Example 42, a polycarbonate plastic, differs from example 36 in that the process parameters in the steps are adjusted as follows:

s2, mixing polycarbonate, a polylactic acid modifier, a compatilizer, ABS resin and other auxiliaries, heating to 280 ℃, and stirring for 150 seconds to obtain a first mixed system;

s3, adding carbon-based fibers and a reinforcing auxiliary agent into the first mixed system, heating to 290 ℃, and stirring for 30S to obtain a second mixed system;

Example 43, a polycarbonate plastic, differs from example 36 in that the process parameters in the steps are adjusted as follows:

s2, mixing polycarbonate, ABS resin, carbon-based fiber, polylactic acid modifier, compatilizer, reinforcing additive and other additives, heating to 280 ℃, and stirring for 150 seconds to obtain a first mixed system;

s3, performing injection molding on the first mixed system, wherein the injection pressure is 150MPa, the mold temperature is 140 ℃ during injection, the screw rotation speed is 30rpm, after the injection is finished, the mold temperature is cooled to 70 ℃ at the speed of 8 ℃/min, and then demolding is performed.

For the above examples, the following comparative examples were set and compared.

Comparative example 1, a polycarbonate plastic, differs from example 1 in that the PC/ABS composite prepared by the method of example 1 under the authorization publication No. CN101328310B was injection molded, specifically as follows: the weight percentage of PC resin is 64.2 percent, the weight percentage of ABS resin is 15 percent, the weight percentage of glass fiber is 10 percent, the weight percentage of HP4051 is 5 percent, the weight percentage of SMA218HF is 5 percent, the weight percentage of KH550 is 0.2 percent, the weight percentage of 1010/168 is 0.2/0.4 percent, the components are mixed uniformly at room temperature in a high-speed mixer, the mixture is produced by a TE-35(L/D is 48) double-screw extruder produced by Nanjing Keya company, and the processing temperature (from a feeding port to a die head) is respectively as follows: 220 deg.C, 240 deg.C, 255 deg.C, 260 deg.C, 265 deg.C, and 30 Hz.

Comparative example 2, a polycarbonate plastic, differs from example 1 in that equal mass of glass fibers are used instead of carbon fibers.

Example 3, a polycarbonate plastic, differs from example 1 in that an equal mass of polycarbonate is used instead of the polylactic acid-based modifier.

Example 4, a polycarbonate plastic, differs from example 1 in that the compatibilizer is replaced by an equal mass of polycarbonate.

Comparative example 5: a polycarbonate plastic differing from example 1 in that equal mass of polycarbonate is used instead of carbon fibers.

The following experiments were now set up for examples 1 to 43 and comparative examples 1 to 5.

Experiment 1: samples were prepared according to the general test method in ISO-527-1-2012, and tested sample 1-1 to test sample 43-1, and comparative sample 1-1 to comparative sample 5-1 were obtained, and tensile properties were measured on the above samples.

Experiment 2: samples were prepared according to the general test method in ISO-178-2010, and test samples 1-2 to 43-2 and comparative samples 1-2 to 5-2 were obtained and tested for flexural strength and flexural modulus.

Experiment 3: samples were prepared according to the general test method in ISO-179-1-2010, and example Nos. 1-3 to 43-3 and comparative sample Nos. 1-3 to 5-3 were obtained, and the impact strength was measured on the above samples.

Experiment 4: samples were prepared according to the general test method in ISO-75-1-2013 to obtain practical sample 1-4 to practical sample 43-4 and comparative sample 1-4 to comparative sample 5-4, and the heat distortion strength was measured on the above samples.

First, the above experimental measurements were performed on examples 1 to 6 and comparative examples 1 to 5, and the results are shown in table 4.

Table 4: results of measurements in examples 1 to 6 and comparative examples 1 to 5

From the experimental data, as in examples 1 to 6, the tensile strength and the bending strength of the prepared plastic sample are closer to those of comparative example 1 and comparative example 2 by using the carbon fiber as a substitute for the glass fiber and adding the polylactic acid system. When the carbon-based fiber is carbon nano tube, the material has higher bending modulus, impact strength and thermal deformation strength, probably because the carbon nano tube has a larger conjugated system and a more rigid aromatic ring structure, the material has better rigidity and heat resistance.

In comparative example 3, the use of polylactic acid was excluded, resulting in a large reduction in the flexural strength and a small reduction in the flexural modulus of the material. The polylactic acid material is an environment-friendly material, has good crosslinking performance, and the long chain of the polylactic acid material can form a crosslinking structure with the carbon nano tube to a certain degree and has good flexibility, so that the polylactic acid material is beneficial to improving the strength and the toughness of the material. Therefore, the use of polylactic acid is excluded, which results in the material becoming brittle and thus adversely affecting the use. In example 4, the absence of the compatibilizer resulted in poor dispersion of the polylactic acid, the carbon nanotubes and the polycarbonate, resulting in an uneven overall structure and adversely affecting the properties of the material, such as tensile strength and flexural strength. Comparative example 5 excludes the use of carbon-based fibers, resulting in a significant reduction in the toughness, strength, and heat resistance of the material as a whole.

The results of comparing example 1 with examples 7 to 12 are shown in Table 5.

Table 5: measurement results of example 1 and examples 7 to 12

According to the data, the composite system formed by grafting the polylactic acid and the chitosan is favorable for improving the overall tensile strength. The chitosan has more active groups, can form dipole interaction with the end groups of a plurality of macromolecules in a system, and even generates covalent bonds, thereby being conductive to forming a more stable crosslinking system and being conductive to improving the tensile strength of the material. Meanwhile, the chitosan also has the function of inhibiting the degradation of polylactic acid in the processing engineering, thereby improving the heat resistance of the material. In example 12, the carbon nanotube was further subjected to nickel plating treatment using chitosan-grafted polylactic acid, and the mechanical properties such as rigidity and wear resistance of the carbon nanotube were further improved. And after nickel plating, the surface of the carbon nano tube is easy to form a cavity structure, has stronger activity, and is easier to form a net structure with active groups at two ends of an adsorption polymer chain, thereby playing a role in improving the tensile strength.

Further, the results of comparison of examples 12 to 28 are shown in Table 6.

Table 6: data of test results in examples 12 to 18

According to the data, after the reinforcing additive is added, the tensile strength, the bending strength, the impact strength and the heat resistance of the whole material can be further improved. After the epoxy resin is added, the tensile strength and the impact resistance are mainly improved, the bisphenol A epoxy resin has the characteristics of rigidity and flexibility and has better crosslinking performance, and the bending modulus is also improved under the condition of improving the tensile strength. When the epoxy equivalent of the epoxy resin is reduced, the ability to form a crosslinked structure is weakened, and the epoxy resin itself has a certain brittleness, which deteriorates the overall bending strength in the system, but has a positive influence on the tensile strength, impact strength and heat resistance. In addition, the overall properties are less affected by selecting other types of epoxy resins.

On the basis of epoxy resin, the toughness of the system can be greatly improved by further adding the polyurethane elastomer, and the polyurethane elastomer can play a role in improving the flowability, so that the agglomeration of carbon nanotubes is avoided, the system is more uniform as a whole, an excessive pi-bond stacking system is not suitable to be formed locally, the toughness of the whole material is increased, and the material is not easy to break. At the same time, the more uniform system also contributes to the improvement of the overall mechanical strength, such as impact resistance, tensile strength, and the like. The gelatin is further added to serve as a reinforcing aid on the basis of the epoxy resin and the polyurethane elastomer, the gelatin can play a role in assisting and promoting the crosslinking effect between the materials, and meanwhile, the gelatin can well contain the carbon nano tubes, so that the carbon nano tubes are not easy to agglomerate, and the uniformity and the strength of the material are further improved.

It is understood from examples 27 and 28 that the use of chitosan-grafted polylactic acid or the addition of the reinforcing aid to the nickel plating treatment of carbon nanotubes contributes to further improvement of the overall properties of the material, and has a good effect.

The results of experiments 1 to 4 performed on examples 29 to 36 are shown in Table 7.

Table 7: results of the Performance test of examples 29 to 36

From the above data, it can be seen that the addition of other adjuvants has a minor effect on the mechanical properties of the material, but it still has a significant effect. For example, the color master batch is added for color adjustment, and the color master batch is added in the proportion, so that the polycarbonate plastic has bright color on the premise of having great influence on the whole structure. The lubricant is added to assist demoulding, which helps to improve production efficiency. The antioxidant can serve the purpose of prolonging the service life of the polycarbonate plastic.

The results of tests 1 to 4 conducted on examples 37 to 43 are shown in Table 8.

Table 8: results of Performance test of examples 37 to 43

From the above data, it can be seen that the internal structure of the plastic can be made more uniform by processing with the methods of examples 36 to 38, which contributes to the improvement of the mechanical strength in all aspects. In example 39, the use of a lower temperature directly during demolding increased the internal stress in the material, which in turn led to an overall embrittlement of the material. In examples 40 to 43, the mixing sequence of the raw materials was changed, which also resulted in uneven distribution of the components, and further affected the uniformity and mechanical properties of the whole raw materials.

To sum up, the technical scheme in this application uses carbon base fibre to replace glass fiber on prior art's basis to additionally added polylactic acid material, thereby improved production and security of using. Furthermore, in the application, a polylactic acid system is grafted by the carbon nano tube with the nickel plated surface and the chitosan, and epoxy resin, a polyurethane elastomer and gelatin are added as reinforcing aids, so that various performances of the material are further improved.

The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A polycarbonate plastic characterized in that: the material is obtained by injection molding of the following components in parts by mass:

polycarbonate (C): 50-80 parts;

ABS resin: 7-15 parts;

carbon-based fibers: 5-10 parts;

polylactic acid modifier: 3-6 parts;

a compatilizer: 2-3.5 parts;

a reinforcing auxiliary agent: 0-4 parts;

0-6 parts of other auxiliary agents.

2. A polycarbonate plastic in accordance with claim 1, wherein: the carbon-based fiber is a carbon nano tube, and the carbon nano tube is activated by mixed acid.

3. A polycarbonate plastic in accordance with claim 2, wherein: and the carbon nano tube is activated and then subjected to surface nickel plating treatment.

4. A polycarbonate plastic in accordance with claim 2, wherein: the polylactic acid modifier is a chitosan grafted polylactic acid compound.

5. A polycarbonate plastic in accordance with claim 2, wherein: the reinforcing additive comprises 1.2-2 parts by mass of epoxy resin, and the epoxy value of the epoxy resin is greater than 0.35.

6. A polycarbonate plastic in accordance with claim 5, wherein: the reinforcing auxiliary agent further comprises 0.2-1.5 parts by mass of a thermoplastic polyurethane elastomer.

7. A polycarbonate plastic in accordance with claim 6, wherein: the reinforcing auxiliary agent further comprises 1.5-2.5 parts by mass of gelatin.

8. A polycarbonate plastic in accordance with claim 1, wherein: the other auxiliary agents comprise 0.1-0.5 part by mass of antioxidant, 0-4 parts by mass of color master batch, 0.1-0.3 part by mass of lubricant and 0.3-0.6 part by mass of hydrolysis resistance agent.

9. A polycarbonate plastic in accordance with claim 1, wherein: the compatilizer is maleic anhydride grafted polypropylene.

10. A process for processing a polycarbonate plastic as defined in any of claims 1 to 9, characterized in that: the method comprises the following steps: